Photonic crystals possess a periodically modulated dielectric constant on the scale of the wavelength of light. This influences the local density of optical states, which determine the interaction between the electric field of the structure and an emitter. Especially, forbidden spectral regions can occur, so called band gaps.
This work studied the influence of an inverse opaline structure on the spontaneous emission of trivalent Terbium phosphors. To provide a homogeneous distribution of the luminescence centers and a regular modulation of the refraction index, the whole photonic band material was composed of luminescing material.
A main part of this work concerns of the development of characterization methods for these materials.
It was shown with confocal microscope and cathodoluminescence measurements, that the distribution of luminescence centers was homogeneous through the whole inverse opal.
The self-organized synthesis lead to a low Q-factor of 10 to 20 and to a large number of scattering centers. The average scattering length was determined to be approximately 6 μm.
Nevertheless, a strong influence on the emission spectra was observable. In the region of the wavelength of the bandgap, single spectral lines could be reduced by a factor of 3.0.
This reduction is angle depended because the used material shows an incomplete bandgap. Thus, the spectral composition of the detected light could be controlled with a new set-up, which used objectives with different
numerical appertures.